| 摘要: |
| 借助“中国首次环球科学考察航次”, 在印度洋海区进行了N、Fe、N+Fe 以及N+Fe+P 的营养盐添加模拟实验。通过对实验过程中水体营养盐浓度、叶绿素a(Chl-a)浓度以及温度等参数进行分析,探讨了添加不同营养盐对该实验海区浮游植物生长的影响。结果表明, N 的添加会引起浮游植物的快速爆发, 而单独添加Fe 并不能刺激浮游植物快速生长, N、P 联合作用对浮游植物生长的影响远远大于单独N 的作用。另外, 在实验海区浮游植物优先利用海水中的硝酸盐, 在硝酸根耗尽后, 海水中可被利用的P 会促进浮游植物的生长。实验过程中水体N/P 比值的变化同叶绿素a 浓度以及浮游植物生长速度(R)没有可对比性, 而且N/P 比值与后两者之间的相关性都差, 所以认为水体中N/P 比值并不能单独决定浮游植物生长。此外, 实验水体温度同Chl-a 浓度和R值之间相关性分析表明, 水体温度虽对浮游植物生长有重要作用, 但不能控制浮游植物生长。 |
| 关键词: 印度洋 营养盐 模拟实验 限制作用 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目(40903033,40403004) |
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| Nutrient limits phytoplankton growth in nutrient enrichment experiments with seawater from the Indian Ocean |
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TANG Song
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| Abstract: |
| Nutrient enrichment experiments were carried out in the Indian Ocean during the Chinese First Around-world Researching Cruise, with N, Fe, N+Fe and N+Fe+P being added in the collected surface sea water separately. Varying some parameters in the experimental water, we studied the factors that limited phytoplankton growth, such as the concentration of nutriment, chlorophyll a, temperature, and etc. The addition of nitrogen resulted in phytoplankton blooming, but the addition of iron did not stimulate the growth of phytoplankton. The combined effect of nitrogen and phosphorus to phytoplankton growth was much stronger than that of nitrogen alone. Furthermore, the utilization of nitrogen proceeded that of phosphorus; and the available phosphorus could be utilized by phytoplankton after nitrogen was exhausted. Variation of the ratios of nitrogen to phosphorus in the experimental water did not match that of chlorophyll a concentration and phytoplankton growing rate (R). The correlation between them was weak. So it was considered that the ratio of nitrogen to phosphorus cannot determine the growth of phytoplankton. In addition, water temperature played an important but not a limiting role in the phytoplankton growth in these experiments , as was shown by the correlation between the temperature of experimental water and chlorophyll a concentration or the value of R. |
| Key words: the Indian Ocean nutrient model experiment limitation |
